The present invention relates to power transmissions of the "belt" or "chain" and grooved pulley type, allowing, for equal power, the space required therefor to be considerably reduced, so as to be applied more particularly to speed variators of this type.
As is known, very numerous types of variators exist in industry. All are heavy and cumbersome with respect to the power transmitted, which practically prohibits use thereof in vehicles. We find among them variators of the V-belt or chain and grooved pulley type. The belt variator is cumbersome because of the fragility of its textile belt. The chain variator, in addition to its less smooth operation, is also cumbersome because of the smallness of the surfaces in contact with the driven pulleys.
Other known variators are lighter and they use belts made of metallic strip-irons and with a direct metallic bearing-surface into the groove of the pulleys, of the type described in the German Patent Application published before Examination (Offenlegungsschrift) to HEYNAU No. 2 505 228 and in U.S. Pat. No. 3,949,621 to VARITRAC; those variators allow the transmission of more power than the belts having an elastomeric surface bearing on metal of the type described in the German Patent Application to VARITRAC No. 2 821 698 to which corresponds U.S. Pat. No. 4,213,350 to HOROWITZ; they, however, require a very high tensil stress and are very heavy; moreover, the strip-irons in contact with the transverse elements tend to wear and their manufacture is very complicated due to the necessity of using concentric strip-irons, without weld.
The belt according to the present invention in which the transverse elements are integral with an armature made of steel cable uses the principle of transmission metal on metal and a very strong armature able to take a high tensile stress, while eliminating the drawbacks of the belts made of strip-irons.